People who cite Spock's line from "The Enterprise Incident" as 'canon proof' that Vulcans don't lie are...

Are there really such idiots?

I have run into one or two fans who believe that anything said by any character in any context must be taken as literally and precisely true. They often have to disregard both storyline and characterization to do so, but still...

It's not just a Trekkie thing. This was a perennial source of confusion in the Underworld series, where the Vampire Elders lie all the time about their history, backstory, mythology, etc. This often seemed to fly over the heads of some confused UW fans who took every declaration from Viktor or Marcus as gospel--even when the plot made it very clear that they were constantly rewriting history to suit their own purposes.

"But . . . but Marcus said that killing an Elder would cause all vampires to die. So why didn't Selene die when she killed Marcus?"

Er, because Marcus created that myth for his own protection, as explained mid-way through the second movie.